For patients who have a bacterial infection, the most common cure is administration of antibacterial drugs. Bacterial resistance to such drugs is unfortunately a common development due, for example, to drug overuse and misuse. When patients stop taking antibacterial drugs too early, any remaining bacteria are likely to have increased resistant to the antibacterial drug. Recently, there has been a dramatic increase in the occurrence of bacteria that are resistant to many or all of the commonly used antibacterial drugs. Because multiple drug resistance is a growing problem, physicians are now confronted with infections for which there is no effective therapy.
Strategies to address these issues emphasize enhanced surveillance of drug resistance, increased monitoring and improved usage of antimicrobial drugs, professional and public education, development of new drugs, and assessment of alternative therapeutic modalities. Alternative and improved agents are needed for the treatment of bacterial infections, particularly for the treatment of infections caused by resistant strains of bacteria, e.g., penicillin-resistant, methicillin-resistant, ciprofloxacin-resistant, and/or vancomycin-resistant strains.
Accordingly, there is a need for improved, broad-spectrum antibiotic agents that are effective against both Gram-positive and Gram-negative bacteria, and are also effective against antibiotic-resistant bacteria. Ideally, such agents would show low toxicity to the patient, would be inexpensive and readily synthesized from commonly available starting materials, would exhibit high levels of oral bioavailability, and/or would exhibit high levels of efficacy at relatively low doses.